Apparatus for making siliceous fibers



July 28, 1942.

G. SLAYTER ETAL APPARATUS FOR MAKING SILICEOUS FIBERS Filed Sept. 28,1939 INVENTORS Games Slayter w J Thomas,

ATTORNEY mened July 28, 1942 APPARATUS FOR MAKING SILICEOUS FIBERS GamesSlayter, Newark, and John H. Thomas, Perrysburg, Ohio, assignors toOwens-Coming Fiberglas Corporation, a corporation of DelawareApplication September 28, 1939, Serial No. 296,952

6 Claims.

The present invention relates to apparatus for making siliceous fibers,and more particularly to a novel method and apparatus for forming fibersby mechanical drawing of the glass or other siliceous material to formrelatively continuous filaments or fibers.

This application is a continuation-in-part of our copending applicationSerial -No. 105,405, filed October 13, 1936, which issued as Patent No.2,234,986, March 18, 1941.

Generally, and for the most part, the objects of the present inventionare substantially the same as those set forth in connection with theabove identified application, insofar as actual fiberization isconcerned. Likewise thecharacter of fiber produced is similar to thatproduced by the method and apparatus disclosed in the said applicationinsofar as fineness of diameter, tensile strength, flexibility andweavability, stretchability, uniformity, and fiber continuity areconcernecl. The present invention is primarily concerned withtemperature control which is a necessity in maintaining the properresistance for the attenuation of the fibers.

After the glass has been reduced to the proper size in the form of afiber, it is essential that it is sufficiently cool and viscous so thatit will not continue to attenuate and pull to nothing thus becomingsevered. If the glass is too molten or fiuid at this stage, it will nothave sufiicient resistance to maintain the desired diameter. This isespecially true in high speed production of fibers and in such aninstance the temperature control of the glass from the supply body tothe finished fiber must be accurately maintained throughout.

As explained in our copending application above referred to, withoutadequate temperature control, the attenuation may take placesimultaneously over a long portion of its length. It has been found thatin such a case it is considerably more difficult to regulate the finalsize of the fibers inasmuch as attenuation may not be uniform throughoutthe length of the fiber. Thick and thin spots and other irregularitiesmay thus be present. Moreover, attenuation over a long range produces afiber having a multiplicity of minute strains, checks, anddiscontinuities, particularly at the surface.

The present invention is concerned with a novel method of temperaturecontrol which under certain conditions of manufacture may be moreadvantageously employed than the method disclosed in the aboveidentified application or than other methods heretofore employed.

It is among the principal objects of the present invention, in anapparatus of the character set forth in the above cited application, toprovide an improved apparatus wherein accurate control of thetemperature, and consequently the fluidity, of the fibers undergoingattenuation may be attained.

It is an equally important object of the invention to provide a meanswhereby the temperature of the bushing nipples from which the attenuatedfibers emanate may also be controlled to produce fibers of a desiredcharacter and to prevent clogging of the bushing nipples duringproduction of the fibers.

Another object of the invention is to provide a temperature controlapparatus of the character wherein the fibers undergoing attenuation areprotected from the deleterious effect of dust or other suspendedparticles in the atmosphere and wherein such dust is excluded from theattenuating region and is thus maintained out of contact with the glassfilaments undergoing fiberization.

In carrying out the above mentioned objects, the invention contemplatesthe provision of an electrically or otherwise heated metal bushinghaving a plurality of orifices therein for feeding the molten glasstogether with a plurality of blowers which are positioned beneath thebushing and which are so located that jets of air or steam issuing fromthe same are directed against the bushing nipples and against thestreams of molten glass issuing from the latter in such a manner thatboth the nipples and the streams issuing therefrom may be maintained atthe proper temperature for most emcient attenuation of the fibers.

In a temperature control apparatus of this character, the blowers abovereferred to may be located in close proximity to the bushing and may beso adjusted that the jets issuing there from are largely confined to thevicinity of th" bushing nipples, thus not only rendering the spaceimmediately below the bushing accessible to the operator but also makingit possible to bring the mechanical attenuating means into closeproximity to the bushing. Such an arrangement is particularlyadvantageous in the production of crimped fibers by means of attenuatinggears, in that it permits the combined mechanical attenuating andcrimping mechanism to be located well within the attenuating regionwherein the fibers may be still'more or less plastic and subject to thecrimping operation.

Other objects and advantages of the invention. not at this timeenumerated, will become apunderstood. H I

In the accompanying single sheet of drawings:

Fig. 1 is a side elevatlonal view, partially in section and diagrammaticin its representation,

36! an electrically heated bushing to which the improved temperaturecontrol apparatus has been applied;

Fig, 2 is a bottom plan view of the apparatus shown in Fig. 1; and

- parent as the nature of the invention is better emerging from thenipples i 8 are drawn. An attenuating means which may be in the form ofa Winding or packaging spool 30 is provided to draw the fibers andwindup the thread as it is being formed. The grouped fibers, afterhaving passed through the guide .28, are in parallel and closerelationship and form a strand T which is wound upon the packaging spool30 at high speed.

The arrangement of parts thus far described is more or less conventionalin its design and no claim is made herein to any novelty associatedtherewith,'the,novelty of the present application residing ratherin thenovel temperature control I means now to be more fully described.

tirety by the reference character I0 and includes I a metal bushing I2in which a supply body (3' of molten glass is contained. The bushing l2preferably tapers downwardly and inwardly. as at l4 and is formed with arelatively narrow bottom wall l8 provided with a plurality of nipples l8which are preferably arranged in parallel rows as shown. The nipples iiiare formed with orifices I9 therethrough from which the molten glassissues to be attenuated into fibers. While in Figs. 1 and 2 there areillustrated two rows of nipples, it its to be distinctly understood thata greater or lesser number of such rows may be employed, depending onthe character of the thread to be The temperature control meanscomprising the present invention comprises a pair of opposed blowers 3|in the form of elongated tapered hollow members which are positionedbeneath the unit I on opposite sides of the rows of nipples l8' and aresubstantially coextensive with or slightly longer than the latter.Aplurality of inwardly directedjet openings 32 are preferably providedat the inner sides of the blowers and air, steam,vor other cooling fluidadmitted to the blowers 3| from a manifold conduit 34 and branchconduits 36 is expelled through the jet openings 32 and directedinwardlytoward the nipples l8. Generally only a relatively small amount ofpressure such as to 5 pounds is sufiicient in said produced as, thefinal product. Likewise the number of nipples contained in each rowmaybe varied to accommodate composite threads which are composed of avarying number of individual filaments.

In order to produce exceedingly fine fibers it.

has been found desirable to draw from a relatively small cross-sectionalarea of exposed molten glass. For example, successful attenuation hasbeen achieved from nipples which-were in a range of from .02" to .08" indiameter, these figures being subject to variation in accordance withparticular degrees of attenuation, etc. de-

high,temperature refractories or alloys capable of withstandingtemperature above or near the clevitrification point of the particularglass contained in the bushing I2 may be used if desired The bushing I2is surrounded by a refractory insulating medium 20, theentiremelting'unitl0 being suspended by means of hanger studs 22 and anglepieces 24.

Formed'on or connected to the opposite ends of the bushing l2 adjacentthe bottom thereof are a pair of terminal ears or lugs 26 to whichconductors (not shown) may be connected for regulably supplyingelectrical current to the bushing in order that the latter'may'be heatedin the lower regions thereof by direct resistance of the metal of thebushing.

Disposed below the melting unit I0 is a gathering eye or guide 28 in theform of a concave surface around which the multiplicity of fibersblowers. a

The jet' openings 32 are preferablylocated relatively close to eachother and preferably exceed in number the number of nipples I8 in eachrow thereof in order that the streams of cooling fluid issuing therefrommay become intermingled and lose their identity prior to contact withthe nipples l8 or streams of glass issuing therefrom. In other words, byclosely spacing the jet openings 32, no pin point blasts of air or otherfluid impinges upon the streams and a smooth blast of air which issubstantially coextensive with the rows of nipples I8 is produced. Ifdesired, the jet openings may be sufilciently wide to merge mto a singleslot although generally greater economy of air may be effected withsmaller openings.

The jet openings 32 are preferably directed at an angle to the nipplesl8 in such a manner that the streams impinge not only against thenipples but also against the glass issuing therefrom in the direction ofmovement thereof and thus fiberlzation is facilitated.

Disposed between the blowers 3| and the refractory medium 20 are a pairof baflie plates 31 which are secured to the angle pieces 24 by means ofstuds38. The plates 31 also serve as an additional support for therefractory medium 20. Adjustably mounted on the studs 38 are a'pluralityof blower clamps 40, each having an adjustable inner section 42which bears against its respective blower 3i and clamps the same firmlyagainst one of the baflie plates 31.

The baflie plates 31 are provided with down wardly and inwardly inclinedsurfaces 44 against which the blowers 3|v bear and which terminate inclose proximity to the lower end l6 of the bushing I2. The inner ends ofthe plates 31 are cut away'as at 45 to provide a clearance space inorder that these inner ends will not be excess'ively heated. by directcontact with the insulating medium near the casting. Air or othercooling fiuid issuing from the Jet openings 32 passes over the inneredges of the plates 31 and impinges on the'fibers at the base thereof inthe vicinity of the orifices l9 from which the streams of molten glassemanate. The fluid issuing from the jetiopenings 32 may if desired becaused to impinge directly upon the lower extremities of the nipples I8as well as upon the fibers at the base thereof where the same areplastic. In this manner the air or other cooling medium cools the lowerextremities of the nipples and also passes along a portion ofthe exposedsurface of the glass. During attenuation'of the fibers when theattenuating means 30 is in operation the air or other fluid issuing fromthe jet openings 32 may assist attenuation to a certain extent. If forany reason whatsoever the attenuating operation is ceased, the blasts ofair will keep the glass moving slowly and the orifices I9 clean andprevent clogging of the orifices ID by virtue of the glass wetting theoutside surfaces of the nipples I8.

In actual operation it is most desirable to atv tain relatively hightemperatures within the bushing I! in order to result in completesolution of the ingredients of the glass and also in order that theglass may become sufiiciently fiuid' to fiow freely through the smallorifices I9 of the nipples I8. By the present temperature control systemin which the cooling fiuid is caused to impinge either directly upon thelower ends of the nipples or upon the streamsoi glass immediately belowthe orifices, or both, the relatively hot glass which at this hightemperature would or dinarily not be susceptible to the attenuatingoperation because of its high liquid state is'rendered sufilcientlyviscous in the vicinity of the nipples to permit attenuation thereof.Theobject sought is to pull or attenuate the glass at as low a viscosityas will permit the same to be attenuated into a fiber.

In Fig. 3 the bushing H2 is shown as being formed with a row of nipplesH8 having orifices IIQ. Attenuating gears I80 are employed for drawingthe fibers from the orifices I I9. The attenuating gears I30 areslightly longer than the row of nipples H8 provided in the bushing andthe fibers are each drawn directly downwardly between the gears I30which are rotated in oppositedirections at high speed. Where fibers of astraight character are desired, the gears I30 may be located well belowthe bushing I I2 in a region removed from the region of plasticity ofthe fibers being attenuated. If however crimped fibers are desired, thegears I30 may be located as shown in dotted lines in the vicinity of thenipples H8 and within the region of plasticity of the fibers. In thismanner the fibers upon entering between the teeth provided on the gearsI30 become distorted and crimped as shown in dotted lines.

Because of the fact that the blowers I3I are positioned on oppositesides of the bushing II? and substantially on a level with the lower endof the latter, ample room is available beneath the bushing forpositioning of the attenuating means. The blowers serve to impinge airupon the glass at the orifices while it is still in a mo]- ten,unfiberized state and increases its viscosity so that filaments may bedrawn at extremely high speeds with a minimum length of attenuation.

Modifications may be resorted to within the spirit and scope of theappended claims.

We claim:

1. Apparatus for forming a substantially continuous fine glass fibercomprising a glass melting unit including a metal bushing having anorifice at the bottom thereof, an insulating mem-- her surrounding thebushing at the sides thereof and extending downwardly to aregion'adjacent the bottom of the bushing, said member having outer surfacessloping upwardly and away from the bottom of the bushing, a pair ofbailie plates in contact with said surfaces on opposite sides of thebushing and terminating adjacent said orfice, a blower in contact witheach bailleplate, and means for clamping each blower against itsrespective baflle plate, said blowers having jet openings thereinarranged to direct blasts of cooling fluid under pressure over the endsof said bame plates and against the glass issuing from the orifice torapidly cool the glass issuing from the orifice.

2. Apparatus for forming a substantially continuous fine glass fibercomprising a bushing for containing molten glass and having an orificein its bottom wall for exposing the molten glass, cooling blowersarranged in proximity to said orifice on opposite sides-thereof andlocated substantially wholly above the leveloi the orifices and ,havingjet openings directed toward the orifice for directing substantiallyhorizontal blasts of cooling gases under pressure over said orifice andthe glass issuing from the latter to rapidly cool the glass.

3. Apparatus for forming a substantially continuous fine glass fibercomprising a bushing for containing molten glass and having an orificein its bottom wall for exposing the glass, a blower positioned inproximity to said orifice and having a jet opening therein directedtoward the orifice and arranged to direct a blast of cooling fiuid underpressure over said orifice and the glass issuing from the latter torapidly cool the glass to solidification, said blower beingsubstantially fiat thereof and extending downwardly to a region adjacentthe bottom of the bushing, blowers respectively at opposite sides ofsaid bushing provided with jet openings directed toward said orifice,said blowers being substantially fiat in cross-section and locatedclosely adjacent the bottom of the insulating and supporting member andat a level at least as high as the level of the orifice. and means forclamping said blowers to said insulating and supporting member in suchposition.

5. Glass fiber forming apparatus comprising a glass melting unitincluding a narrow elongated metal bushing for containing molten glassand having plural rows of orifices in its bottom wall, said rowsextending in the direction of length of said bushing, an insulating andsupporting member surrounding said bushing and extending downwardly to aregion adjacent the bottom of the bushing, and blowers arrangedrespectively at opposite sides of said bushing and located closelyadjacent the bottom of said insulating and supporting member, saidblowers being substantially fiat in cross-section and being located at alevel at least as high as the level of the orifices, and each of saidblowers being provided with a series of jet openings extending the fulllength or the rows of orifices and directed toward said orifices.

' .6. Glass fiber forming apparatus comprising a meta1 bushing forcontaining molten glass and having-plural rows of hollow nipples on itsbottom wall through which said molten glass flows, an insulating andsupporting member surrounding said bushing and extending downwardly to aregion adjacent the bottom of the bushing, the bottom wall of saidinsulating member sloping upwardly away from the bottom or said bushing,

memes blowers respectively at opposite sides 0! said bushing in contactwith said inclined bottom wall and each provided with a series of jetopenings extending the full length of said rows of nipples and directedtoward said nipp1es,"said blowers being substantially wholly positionedabove'the level of said nipples, and means for clamping said blowers tosaid insulating and supporting member in such position.

GAMES SLAYTER. JOHN H. THOMAS.

